Working with the nRF52 Series' improved APPROTECT

RE: Working with the nRF52 Series' improved APPROTECT

J.P. Hutchins — Fri, 26 May 2023 19:01:06 GMT

Generally, I'd like security like

1) Enabling a secure immutable bootloader (locking that flash region), signing/encrypting updates, etc
2) Locking debug port access

What concerns me, is that it seems like the debug port access lock can be undone by erasing all flash through CTRL-AP. Is there a way to lock the debug port access and make it impossible to gain access again?

Technically I would prefer something like requiring a key to unlock the DAP but if that's not possible then I'd like to know if it's possible to lock the DAP irrevocably.

RE: Working with the nRF52 Series' improved APPROTECT

Tomasz — Tue, 21 Feb 2023 12:02:58 GMT

I have a project with SDK 15.2 and would like to upgrade the protection possible with the new release of silicon but
possibly avoid interfering with the app code and keep build environment the same for the app the same as it was.
As the bootloader is the very 1st bit of code to run, and I can update it independently, isn't that the only part needs to be rebuilt with the latest MDK?

RE: Working with the nRF52 Series' improved APPROTECT

abhay_kr — Wed, 12 Oct 2022 12:09:04 GMT

Thanks for sharing

RE: Working with the nRF52 Series' improved APPROTECT

toastedowl — Thu, 05 May 2022 15:07:30 GMT

I have been using NRF52832 Rev 2 and I'm trying to move to Rev 3.

I'm using SEGGER Embedded Studio on a MAC. I'm using NRF5 SDK version nRF5_SDK_17.1.0. I downloaded nrf_mdk_8_46_0_gcc_nordiclicense and copied all of those files into the nRF5_SDK_17.1.0_ddde560\modules\nrfx\mdk directory, overwriting what was there.

I have 2 projects: an application and dfu/secure_booloader and I have added ENABLE_APPROTECT to the preprocessor definitions.

When I use nrfjprog, I get 0xFFFFFFFF

1) nrfjprog --recover

2) nrfjprog --memrd 0x10001208

RESULT: 0xFFFFFFFF

I am doing this on a Rev 2 while waiting for my Rev 3's. Is this expected and will the behavior be different if I do the same thing on a rev 3?

RE: Working with the nRF52 Series' improved APPROTECT

Jay Tyzzer — Tue, 15 Mar 2022 21:22:24 GMT

Excellent read. Thanks Daniel!!